1. Field of the Invention
This invention relates to a ventilator system for removing odorous air from toilet bowls, and more particularly to the type of toilet ventilators which include an air duct in communication with odorous air within the toilet, an air suction device, and automatic electrical control for terminating the ventilation when the toilet is flushed.
2. Description of the Prior Art
In addition to applicants pending applications Ser. Nos. 434,519, 496,954, and 540,538, others have disclosed toilet ventilators which include automatic controls for terminating ventilation when the toilet is flushed. The following patents are illustrative: U.S. Pat. Nos. 1,342,716, and 2,881,450.
U.S. Pat. No. 1,342,716 teaches a normally open switch which is automatically closed when the toilet seat is occupied, initiating the ventilator. A special linkage engages the ball cock float within the water tank when the water level falls a predetermined amount after the toilet is flushed. This causes the switch to open, terminating the ventilation.
U.S. Pat. No. 2,881,450 teaches a switch which is operated by an auxiliary float which senses the water level within the water tank. When the toilet is flushed, the water level falls, and the switch changes states at a predetermined water level, terminating the ventilation.
3. Advantages Over the Prior Art
A problem develops when the above methods of control are employed in toilet ventilators of the preferred type in which the water tank air pressure is reduced below atmospheric pressure, by means of an air suction device, so as to cause odorous air to flow from the toilet bowl via the water tank overflow duct. With the float operated switches above, there is necessarily a time delay between the flushing of the toilet and the termination of ventilation, because the water level must fall in order for the float to operate the switch. The air suction remains applied during this interval, and retards the normal rapid flushing cycle of the toilet, inasmuch as the air suction subtracts from the water head in the water tank. The present invention eliminates this time lag, and the resulting problem by means of a sensor which is responsive to water in the overflow duct of the water tank, at the moment the toilet is flushed, whereby ventilation is terminated at this same moment. The invention is suitable for use with all known types of electrically controlled toilet ventilators. The invention allows the use of large air flow, and low air pressure, without causing flushing retardation.